Rock-drill attachment.



H. H. HUGHES.

- ROCK DRILL ATTACHMENT.

Patented Nov 2, 1915.

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v y Y ROCK-DRILL ATTACHMENT.'

To all whom it may concern Be it known that I, HARRY HUGHES; a.

citizen of the United States, fresiding at Poultney, in the countyof'Butland and State of vermont haveinventedcertain new 1 and usefulImprovements in Rock-Drill Attachments, of which theq-followingis ,aspecification. I a.

This invention has for its primary obgect the provision (if-simple andefficient means whereby the bridges or webs left between adjacent holeswhichv are formed by a rock drill may be broken down and the rock splitalong the desired line of cleavage; Hereto= fore'the generally approvedmethod of splitting the rocks was to drill a line of holes by the use ofthe rock-drilling machine; and then manually break down the interveningwalls or webs by means of -a broach held by oneworkman and blowsdelivered upon the said broachby hammers in the hands of other workmentoslowly break away-said intervening webs or bridges. This operation waslaborious and time-consuming and, 1 therefore, expensive- By the use ofmy improved attachment the intervening, webs or 1 bridges may be readilycut away by the use of any rock drill andwithout requiring theremoval ofthe pawls by which the ordinary drill bitisrotated in the usualoperation of the drilling machine. The attachment invented by me is alsoadvantageous in that a rock drill may .be frequently employed inlocations and in circumstances where the use ofa channeling machine isimpracticable 1 or impossible. My 1nvent1on,-therefore, con-,

templates the provision of a .tool which may be; used in any rock drilland which will be driven into the hole without requiring any changeinvthe manner of operatingthe drill- 7 ing machine; The invention alsoseeks to showing myattac mer t in operative. prosi-u provide a toolwhich may be driven into a deeper hole, without change of any of theparts, than has been possible with tools here'- tofore provided, andfinally the invention seeks to improve generally the construction p andarrangement of parts whereby the en ficiency of a rock drill may beincreased. 1

The invention is illustrated in the accom panying drawings andconsistsin certain: novel features which will be hereinafterfirst fullydescribed and. then morefparticularly pointed out in the claimsfollowing the de se-:* i To f revent rotation of the cutter- 1 n the:

scription.

In the drawiim s Figurel is an elevation;

' Specification bf Letters 'latent. 7

tion with' the cutter lowered in the hole, and illustrating-the loweredposition of the drill invention; Fig. 3 isa perspectiveview of thesame;Fig. 4 is a detail-perspective View of the thrust receivin'g-disk;

Thedrilling machineyindicated at 1, m

be of any; desired construction :and is equipped with a chuck 2 adaptedto receive the shank of a drill :bit in the usual manner the said shank;being retained in the chuck by v means of a clamping bolt 3 inserted 9 IV Patented Nev. 2,1915? Application filed May ia a iswseriaino; 838,117;i

through "the'chuck, aswill be readily under stoodr In carrying out myinvention I em-w ploy a; hammer or piston 4 which is pro:

vided with'sa shank 5 adapted to fit within thedrill chuck 2 andbe-secured-thereinzin the same manner as the-shank of the ordi narydrill bit. This piston or 'hammerl is provided with a socket 5vin itslower end which is adapted to receive the upper end of a guide 6 whichmay be secured in said socket in any desired manner but is preferablythreadedinto the same; as illustrated,"

so that'it may-be, readilyremoved'when necessary. This-tubular guide 6is tapered asshown'at 7, so that-it may readily enter the hole formed bythe drill bit, and in 1 length it exceeds the-stroke of the drill so"that, when inuse, the guide will-always be 111 engagement with the shankof the cutter and will=thereby efi'ectuallyjguide the same to the limitof the-feed of'the' drilling 'ma-;

chine. A diskh8', which maybeof soft steel, or any metal more suitableto the purpose, is fitted in the upper end "of the socket 5 over thedevice; The illustrated'cutter consists of a stem or bar 9 which ispreferablyfiatsidedand has lateral 'fins or blades 10 at its lower end,thesaid bladesojr finsbeing dis- .95 the end of the guide, 6 so as toreceive the, thrust of the drilling machine infthe use of housing aguide 61 loosely ,enough to permit f.

free movement ofathe guide upon the shank,

but also snu'glygenough,toprevent lateral vibration of the cutter:v vhenthe; device is in o emount ng d'evi ceisojithat the work 1 and extendsbeyond the ends ofthe bars 12" and is equipped with locking nuts 15 tore-' tain a handle 16 upon the eyebolt. This handle 16 may be held bythe operator or may be extendedup to the cylinder or body of thedrilling machine and fitted in suitable holding and guiding meansthereon. It will be readily understood that the engagement of the bars12 with the fiat sides of the stem 9 will preventrotation of the stemand inasmuch as the blades 10 extend in planes parallel with the fiatsides or" the stem the posi tion of the blades will be known even thoughthey may have reached a deep level in the hole. In the operation of thetool, the cutter occasionally strikes a flinty or hard surface whichtendsto deflect it from its straight course and this action tends toform spiral grooves in-the walls otf'the hole, but the wrench shown anddescribed effectually re-' sists and overcomes the tendency of thecutter to be'defiected in the described manner.

It is thought the operation of my improved attachment will be readilyunder stood from the foregoing description taken in connection with theaccompanying drawings. The line of holes is formed by the operation ofthe drilling machine in the usual manner. The drill bit is then removedfrom the chuck and my improved hammer 4. and guide 6 are substitutedtherefor. The broach, consisting of the stem 9 with its blades 10 andshank 11, is then placed in position with its shank fitting in the guide6 and its blades 10 resting upon the webs between adjacent holesextending in the line of the holes or desired line of cleavage. Thedrilling machine is then operated in the usual manner; the chuck willreciprocate with the piston of the machine and this reciprocatingmovement will be transmitted directly to the piston 4 and the housingguide 6. The guide 6 will reciprocate upon the shank of the cutter andthe blow delivered by the piston of the drilling machine will betransmitted to the upper end of the shank 11 through the piston 4, theforce of the blow belng expended in the contact of" the disk 8 upon theupper end of the shank, as Wlll be read1ly understood. Inasmuch as thetube 6 in the illustrated arrangement has a circular bore and fitsloosely upon the shank 11 having a circular cross-section, it

may rotate about the same without impart ing rotary movement to thebroach and, consequently, the only effect upon the broach will be thedriving of the same against the webs or bridges in the rock so that thesame will be broken away and the broach caused to descend in the holepreviously formed by the rock drill. As above stated, the housing ortubular guide 6 will be longer than the stroke of the drilling machineand, consequently, will be in engagement with the shank 11 at all times,and as the piston is fed forward in the operation of the machine and thebroach consequently driven deeper into the hole, the guide willeventually enter the upper end of the hole and the feeding will continueuntil the lower end of the piston 4: impinges against the upper surfaceof the rock. In actual practice, the entire length of my broach may bedriven into the hole, excepting about one inch of the upper extremity ofthe shank whereas in tools which have been heretofore provided, so faras I am aware, over five inches was left exposed above the rock when themachine had been operated to the limit of its movement.

It will here be noted that the guide 6 of the hammer is slidably mountedon but freely separable from the shank 11 of the cutter so'that afterthe ledge is cut, the chuck carrying the guide 6 may be readily detachedfrom the shank of the cutter by elevating the chuck in the usual manneruntil the lower end of the guide 6 clears the upper end of the'shank ofthe cutter. Such a construction not only permits the cutter to beactuated by the impact of a hammer in cutting theledge but also permitsready detachment of the guide from the cutter without the necessity ofremoving screws, bolts and similar fastening devices usually employedfor connecting the cutter to the guide. Again,it will be noted that theimpact disk 8 is locked in position on the head L or" thehammer byengagement with the upper end of the guide 6, while the enlarged head tof the hammer not only affords sufficient weight to drive the cutterwhen the drill is reciprocated, but by engagement with the rock orsurface of the ground serves as a stop to limit the'downward movement ofthe guide within the opening in the rock.

It will be readily noted that my improved attachment may be applied toany rock drilling machine and will not require any change in theconstruction or manner of operating the same. When the thrust disk 8 hasbeen worn through long continued use, it may be readily removed and anew disk substituted without requiring the provision of a new piston andguide and, con- 1 tion of the tool.

thereof so that there will be no lateralvibra-j The wrench orholder 12'7 may be readily adjusted to any desired an-,

gle by suitable manipulation of the nuts mounted upon the bolts by whichthe sev eral parts of the same are connected, and the cutter will movefreely forward through the said wrench or holder while at the same timerotation of the cutter will be efiectually prevented by the same.

It will be noted that the guide is not attached to the cutter so thatthere is no lifting action exerted on the cutter which is simply drivenahead and, consequently, there is no liability of either the cutter orthe guide breaking andrendering the machine inoperative; Moreover, thecutting end or face of the tool maybe formed on the end of the shank andthe. use of screws or other fastenings are unnecessary. Thisconstruction reduces the cost of manufacture and produces a strongertool and also permits the use of a long shank so that it is notnecessary to suspend operations at frequent intervals in order to changethe tool as the hole gets deeper. The guide is not packed to form an airtight joint with the shank of the cutter but it is imperforatethroughout its length. If the tool be hol low, that is, have aboreextending through its entire length and opening through both itsends, on the up-stroke of the hammer and guide some air will be drawninto the guide and upon the downstroke this air will be forced throughthe hollow bore of the tool and out at the lower end of the same whereit will blow away the dust and keep the work clean of former cuttings.

vting point.

Moreover, the shank of the tool should tend to upset under the force ofthe blows delivered thereonrby the engine and the hammer, this tendencywill be counteracted by the frictionbetween the inside surface ofthehousing or guide and the outside surface of the tool shank so thatthe shank will bekept smooth and the machine will operate easily at alltimes. 'As the cutter is not lifted until it is withdrawn from the holeafter the work is finished, it will always rest squarelyjon the bed ofrock and will not wear away the corners of the cut- The machine also canbe efficiently operated under a low pressure of steam.

Having thus described invention, what I claim is: i

A hammer attachment adapted to be se-' cured tothe chuck of a rockdrill, comprising a downwardly tapered head provided witha threadedsocket in the lower end thereof, a tubular guiding member threaded Iinto said socket and 'adaptedto loosely tele 1 scope with andreciprocate relative to the shank of a cutting member, and an impactdisk held in the bottom of the socket of the head by the threadedportion of the tubular guidingmember and adapted to impart the hammerblow of the reciprocating head to the shank of the cutting member. 7 eIn testimony whereof I afiix my signature in'presence of two witnesses.-

HARRY H. HUGHES. a 5.

Witnesses i THos. 'J. ROBERTS, J OHN R. MAHAR.

Copies of this patent may be obtained for five cents each,by'addre'ssing the Commissioner of Patents,

WashingtomnC. I

